Vehicle control system and automobile using the same

ABSTRACT

A low-cost vehicle control system and a car using the system controls radiation of an actuator driver and thereby reduces the radiation component cost and allows downsizing of an electronic control unit to improve the versatility. The vehicle control system has an electronic control unit, a plurality of actuators and actuator drivers for driving the actuators at the actuator side. The actuator drivers, respectively, have an independent self-diagnosis section, a self-protection section, and a communication control section and are dispersed correspondingly to the actuators.

BACKGROUND OF THE INVENTION

The present invention relates to a control system of a vehicle such as acar and an automobile using the same, particularly to a vehicle controlsystem capable of reducing the cost of the control system and anautomobile using the same.

FIG. 11 is a block diagram of a conventional vehicle control system of acar or the like.

The vehicle control system 60′ is constituted of an electronic controlunit (ECU) 1′, a plurality of sensors 2′, and a plurality of actuators 3a′, in which a predetermined operation is performed by the electroniccontrol unit 1′ set in a cabin in accordance with signals of the sensors2′ provided in the engine room of the vehicle to drive the actuators 3a′.

The electronic control unit 1′ is constituted of an input interface(input I/F) 11′, an arithmetic processing section 10′, and an actuatordriver 4′, in which the input I/F 11′ processes signals sent from thesensors 2′ and outputs them to the arithmetic processing section 10′,the arithmetic processing section 10′ performs predetermined operationsand outputs an optimum signal to the actuator driver 4′, and theactuator driver 4′ drives the actuator 3 a′ serving as a load through aconnector 3 b′. The actuator driver 4′ is concentratedly set in theelectronic control unit 1′.

In the above vehicle control system, an engine control system of a caris a system for optimally controlling an engine by performingpredetermined operations by a microcomputer serving as an arithmeticprocessing section in an engine control unit serving as an electroniccontrol unit in accordance with signals sent from an engine-speedsensor, a water-temperature sensor, and an intake-air-flow sensor,outputting a fuel injection signal to a driver for driving an injectorand a switching signal and a valve-opening-degree adjustment signal to adriver for driving various valves and relay switches.

In the case of the vehicle control system 60′ in FIG. 11, the actuatordriver 4′ is concentratedly set in the electronic control unit 1′.Moreover, there is a publicly-known example in which actuator driversare dispersed not in an electronic control unit but by making thedrivers respectively correspond to an actuator to be driven. Theofficial gazette of Japanese Patent Laid-Open No. 79841/1996 disclosesthe art of a communication connector of a vehicle electronic controllerfor building each of the above dispersed actuator drivers in a connectorconnected to an actuator in order to improve the versatility of theactuator. Moreover, as other conventional examples of vehicle controlsystems, various arts are disclosed in the official gazette of JapanesePatent Laid-Open No. 275801/1999 and the like.

In the case of a vehicle control system, a comparatively large current(approx. several amperes) generally flows through an actuator driverwhen driving an actuator. The actuator driver frequently uses a powertransistor or power MOS in which Joule heat is produced due to anon-resistance because the comparatively large current flows when poweris turned on.

Therefore, as shown by the conventional vehicle control system 60′ inFIG. 11, when the actuator driver 4′ is concentratedly set to one placein the electronic control unit 1′, a problem occurs that the calorificvalue of the whole of the electronic control unit 1′ is increased by theactuator driver 4′ serving as a heat-producing part and the increase ofthe calorific value may affect control.

Particularly, in the case of a recent car, the above electronic controlunit tends to be set not in a cabin but in a vehicle engine room inorder to reduce the harness cost and assembling man-hours and therebythe electronic control unit is exposed to a severer temperatureenvironment. Therefore, to avoid the electronic control unit from beingexposed to the environment, it is necessary to use a radiation componentsuch as a heat sink or radiation fin in order to radiate heat. Thus, aproblem occurs that the manufacturing cost and the cost of the wholevehicle control system in its turn increase.

In this case, as the control system disclosed in the Japanese PatentLaid-Open No. 8-79841 (1996), it is considered to make actuator driversrespectively serving as a radiation component correspond to an actuatorto be driven and disperse the drivers to the actuator side. However, itis not sufficient to merely disperse the actuator drivers because thefollowing are indispensable for a present engine control system: aself-diagnosis function for diagnosing a trouble such as a disconnectionor short circuit of an actuator and communicating the diagnosed state toan arithmetic processing section of an electronic control unit, aself-protection function for preventing an actuator driver from beingbroken down due to overcurrent or overheat when the above troubleoccurs, and a timer circuit when PWM(Pulse Width Modulation)-controllingthe dispersed actuator in a multiplex communication system through aserial communication line.

That is, the present inventor obtained the new knowledge that in thecase of a vehicle control system having an electronic control unit and aplurality of actuators, it is necessary to disperse actuator drivers tothe actuator side in order to reduce the cost of the vehicle controlsystem, provide a self-diagnosis section, a self-protection section, anda communication-control section for each of the actuator drivers andmake the drivers independent in order to keep the reliability andfunctionality of the system even after the actuator drivers aredispersed. In the case of the above prior art, however, the actuatordrivers are not dispersed to each actuator side separately from theelectronic control unit or the actuator drivers are not dispersed toeasily radiate heat even if the drivers are set to the outside of theelectronic control unit. Moreover, the drivers are not independentdrivers capable of constructing an actual system. Therefore, it is notparticularly considered to maintain the reliability and functionality ofthe control system even if reducing the radiation-component cost of thevehicle control system by reducing the heat produced in the electroniccontrol unit and dispersing the actuator drivers.

SUMMARY OF THE INVENTION

The present invention is made to solve the above problems and its objectis to provide a vehicle control system for reducing the cost of thecontrol system by dispersing actuator drivers and controlling the heatproduced in an electronic control unit, making the actuator driversindependent and keeping the reliability and functionality of the controlsystem even after dispersing the actuator drivers and provide a carusing the system.

To achieve the above object, a vehicle control system of the presentinvention is a vehicle control system basically comprising an electroniccontrol unit and a plurality of actuators. The control system hasactuator drivers for driving the actuators at the actuator side and theactuator drivers are made independent by respectively having aself-diagnosis section, a self-protection section, and a communicationcontrol section and dispersed correspondingly to the actuatorsone-to-one.

In the case of the vehicle control system of the present inventionconstituted as described above, the actuator drivers are set to theactuator side separately from the electronic control unit and dispersedcorrespondingly to the actuators one-to-one. Therefore, it is possibleto reduce the cost of the control system by controlling the heatproduced in the electronic control unit. Moreover, because each of theactuator drivers is made independent as a system, it is possible to keepthe reliability and functionality of the control system even afterdispersing the actuator drivers.

Moreover, in the case of a specific mode of a vehicle control system ofthe present invention, the actuator drivers respectively have a timersection.

Furthermore, in the case of another specific mode of the vehicle controlsystem of the present invention, the actuator drivers are built inconnectors or adapters connected to the actuators, removably mounted onoutsides of the connectors or adapters connected to the actuators andelectrically connected with the connectors or adapters, or built in theactuators.

Furthermore, in the case of still another mode of the vehicle controlsystem of the present invention, the communication control section ofeach of the actuator drivers has a serial communication control sectionor a radio communication control section.

Furthermore, the actuator drivers are fabricated on a semiconductorsubstrate and respectively used as an IC or directly mounted on ametallic member not through the substrate and formed integrally withconnectors or adapters connected to the actuators or integrally with theactuators through mold mounting.

Furthermore, the electronic control unit is set in the engine room of avehicle or in a car using the vehicle control system.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood more fully from the detaileddescription given hereinafter and from the accompanying drawings of thepreferred embodiment of the present invention, which, however, shouldnot be taken to be limitative to the invention, but are for explanationand understanding only.

In the drawings:

FIG. 1 is a block diagram of a vehicle control system of firstembodiment of the present invention;

FIG. 2 is a circuit block diagram of an actuator driver constituting thevehicle control system in FIG. 1;

FIG. 3 is an illustration showing the relation between an actuator andan electronic control unit constituting the vehicle control system inFIG. 1;

FIG. 4 is a block diagram of a timer circuit built in the actuatordriver in FIG. 1;

FIG. 5 is a block diagram of a vehicle control system of secondembodiment of the present invention;

FIG. 6 is a block diagram of a vehicle control system of thirdembodiment of the present invention;

FIG. 7 is a circuit block diagram of an actuator driver constituting thevehicle control system in FIG. 1;

FIG. 8 is a top view of a car using the vehicle control system in FIG.1;

FIG. 9 is a sectional view of a connector on whose outside an actuatordriver of the third embodiment is mounted;

FIG. 10 is a sectional view of a connector including an actuator driverof the third embodiment; and

FIG. 11 is a block diagram of a conventional vehicle control system.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be discussed hereinafter in detail in termsof the preferred embodiments of a vehicle control system according tothe present invention with reference to the accompanying drawings. Inthe following description, numerous specific details are set forth inorder to provide a thorough understanding of the present invention. Itwill be obvious, however, to those skilled in the art that the presentinvention may be practiced without these specific details. In otherinstance, well-known structures are not shown in detail in order toavoid unnecessary obscurity of the present invention.

FIGS. 1 to 4 show the vehicle control system of the first embodiment, inwhich FIG. 1 shows a block diagram of the vehicle control system.

The vehicle control system 60 is constituted of an electronic controlunit (ECU) 1, a plurality of sensors 2, a plurality of actuators 3 a,and a plurality of actuator drivers 4, in which predetermined operationsare performed by the electronic control unit in the engine room of avehicle in accordance with signals of the sensors 2 set in the engineroom to drive the actuators 3 a serving as loads through the actuatordrivers 4.

The electronic control unit 1 is constituted of an input interface(input I/F) 11 and an arithmetic processing section 10. The actuators 3a are driven by the actuator drivers 4 and the actuator drivers 4 areset to the actuator-3 a side separately from the electronic control unit1 and dispersed correspondingly to the actuators 3 a.

The actuator drivers 4 are built in connectors 3 b connected to theactuators 3 a and connected with the arithmetic processing section 10 ofthe electronic control unit 1 by one serial communication line 5. Then,the arithmetic processing section 10 captures signals obtained byprocessing signals of the sensors 2 from the input I/F 11, themicrocomputer serving as the arithmetic processing section 10 performspredetermined operations and outputs an optimum control signal to theactuator drivers 4, and the actuator drivers 4 drive the actuators 3 a.

FIG. 2 is a circuit block digram of one of the actuator drivers 4. Theactuator drivers 4 respectively have a self-diagnosis section, aself-protection section, a timer section, and a communication controlsection and are independent so as to make it possible to construct anactual system even if the drivers are set to the outside of theelectronic control unit 1. That is, as shown in FIG. 2, each actuatordriver 4 built in each connector 3 b includes an N-type power-MOStransistor 20, a Zener diode 21, a ground short-circuit diagnosiscircuit 23 for load disconnection or a drain D, a power-supplyshort-circuit diagnosis circuit 24 for over current or the drain D, anda overheat diagnosis circuit 25 respectively serving as a self-diagnosissection, a gate protection circuit 22 serving as a self-protectionsection, a serial communication control section 27 serving as acommunication control section, and a timer circuit 28 serving as a timersection.

The N-type power-MOS transistor 20 is fabricated by using a powersemiconductor process. By controlling the gate G of the transistor 20,the transistor 20 is turned on/off to drive a load 3 aa connected to thedrain D.

The Zener diode 21 is set between the drain D and the gate G. When aninductive load is connected to the drain D, the MOS transistor 20 isprevented from damaging by an electromotive force when the gate G isturned off.

When the ground short-circuit diagnosis circuit 23 for loaddisconnection or the drain D, a power-supply short-circuit diagnosiscircuit 24 for over current or the drain D, or the self-diagnosiscircuit of the overheat diagnosis circuit 25 serving as a self-diagnosissection detects an abnormal state corresponding to each circuit, itoutputs a signal corresponding to the abnormal state to a diagnosisoutput control circuit 26, the diagnosis output circuit 26 outputs asignal corresponding to each abnormal state to the electronic controlunit 1 through a serial communication control section 27.

Moreover, when the self-diagnosis section detects overheat orovercurrent/power-supply short circuit, the section transfers eachtrouble detection signal to the gate protection circuit 22 serving as aself-protection section and thereby turns off the MOS transistor 20 andprevent the transistor 20 from damaging.

The serial communication control section 27 performs serialcommunication with the electronic control section 1, which isconstituted of a controller for controlling the signal transceivingtiming in accordance with the protocol of serial communication and atransceiver for transceiving a signal in accordance with the abovecontrol and receives a driving control signal for each of the aboveactuators 3 a from the electronic control unit 1 while transmitting adiagnosis signal received from the diagnosis output control circuit 26to the electronic control unit 1. The arithmetic processing section 10of the electronic control unit 1 includes a serial communication controlsection (not illustrated) same as the serial communication controlsection 27.

The timer circuit 28 makes it possible to not only a relay switch butalso an actuator requiring PWM (Pulse Width Modulation) driving andpulse driving. That is, the actuators 3 a include an actuator for merelyperforming on/off control such as the relay switch, an actuatorrequiring PWM driving such as a proportional solenoid used to adjustopening degrees of various valves, and an actuator requiring pulsedriving such as an injector. When transmitting driving signals ofvarious types of actuators 3 a through time sharing, it is difficult toregularly transmitting a PWM signal to a specific actuator driver 4.Therefore, the actuator drivers 4 of this embodiment are constituted soas to be able to drive not only relay switches but also actuatorsrequiring PWM driving and pulse driving.

FIG. 3 shows the relation between the actuator 3 a and the serialcommunication line 5.

As shown in FIG. 3, the connector 3 b connected to the actuator 3 a is aconnector provided for front ends of power-supply lines 9 a and 9 b forconnecting the serial line 5 for connecting the actuator driver 4 withthe arithmetic processing section 10 of the electronic control unit 1with the battery of a vehicle and dispersed actuator drivers 4 are builtin the connectors 3 b connected to the actuators 3 a.

Thus, in the case of the configuration of this embodiment for performingmultiplex communication through the serial communication line 5, thenumber of wirings is decreased compared to the configuration (refer toFIG. 11) for individually connecting the electronic control unit 1′ withthe actuator drivers 4′. Power supplies of the actuator drivers 4 arenot restricted to the power-supply lines 9 a and 9 b but it is alsopermitted to use power supplies for supplying power from the actuator-3a side.

FIG. 4 shows a block diagram of a timer circuit 28.

The timer circuit 28 is constituted of a clock generation circuit 30, adividing circuit for dividing a clock generated by the circuit 30, afrequency setting register 32, a duty setting register 33, and a PWMoutput circuit 34.

As described above, to PWM-drive an actuator by the multiplexcommunication system, the electronic control unit 1 transmits a PWMfrequency setting signal and a duty setting signal for the actuatordrivers 4 to the timer circuit 28 through the serial communication line5. These signals are stored in the frequency setting register 32 andduty setting register 33, and an internal clock is divided by thefrequency setting register 32 up to a predetermined PWM frequency andthe divided signal is modulated to a PWM signal having a desired duty.Thereby, to change opening degrees of a valve by changing currents to besupplied to a solenoid, the actuator driver 4 can control the amount ofcurrent to be supplied to the solenoid merely in accordance with a dutysetting signal sent from the electronic control unit 1.

Moreover, the clock generation circuit 30 can self-correct anoscillation frequency in accordance with a waveform pattern sent fromthe electronic control unit 1 at any time, which is realized as aninexpensive circuit without using a crystal oscillator.

When using a serial communication system having a high-enough signaltransmission rate, it is possible to control the actuator 3 a in whichit is necessary to accurately control the fuel injection timing as theabove injector through time sharing by using the actuator driver 4including the timer circuit 28. Moreover, when a signal transmissionrate is low, only the actuator 3 a in which the above timing must beaccurately controlled is controlled from the electronic control unit 1through an exclusive communication line.

FIG. 5 shows a block diagram of the vehicle control system of the secondembodiment.

The vehicle control system 60A has the same configuration as the vehiclecontrol system 60 of the first embodiment except the configuration ofsignal lines between the arithmetic processing section 10 of anelectronic control unit (ECU) 1A and actuator drivers 4A. Therefore,differences between the first and second embodiments are mainlydescribed below.

The actuator drivers 4A of the vehicle control system 60A are set to theactuator-3 a side separately from the electronic control unit 1A anddispersed in connectors 3 b correspondingly to the actuators 3 a.Moreover, the actuator drivers 4A respectively have a self-diagnosissection, a self-protection section, and a communication control sectionand made independent so as to make it possible to construct an actualsystem even if the drivers 4A are set to the outside of the electroniccontrol unit 1A.

Then, the arithmetic processing section 10 of the electronic controlunit 1A is connected with the actuator drivers 4A by a serialcommunication line 5 and a parallel communication line 6, predeterminedoperations are performed by the electronic control unit 1A in accordancewith signals of sensors 2, and a control signal is transmitted from theelectronic control unit 1 to each actuator driver 4A through theparallel communication line 6 to drive the actuators 3 a. However, onlydiagnosis signals of the actuators 3 a sent from the actuator drivers 4Ato the electronic control unit 1A are bundled by the serialcommunication line 5 and transmitted to the electronic control unit 1A.According to the above configuration, it is not always necessary thatthe actuator drivers 4A of this embodiment respectively include thetimer 28.

FIGS. 6 and 7 show the vehicle control system of the third embodiment,in which FIG. 6 shows a block diagram of the vehicle control system.

Because the vehicle control system 60B has the same configuration asthose of the vehicle control systems of the first and second embodimentsexcept the configuration of transceiving signals between the arithmeticprocessing unit 10 of an electronic control unit (ECU) 1B and actuatordrivers 4B, difference points between the third embodiment on one handand the first and second embodiments on the other are mainly describedbelow.

The actuator drivers 4B of the vehicle control system 60 are set to theactuator-3 a side separately from the electronic control unit 1B anddispersed in connectors 3 b correspondingly to the actuators 3 a.Moreover, the actuator drivers 4B respectively have a self-diagnosissection, a self-protection section, a timer section, a radiocommunication control section, and an antenna and are made independentso as to make it possible to construct an actual system even if thedrivers 4B are set to the outside of the electronic control unit 1B.

Moreover, signals are transferred between the arithmetic processing unit10 of the electronic control unit 1B and the actuator drivers 4B throughradio. That is, the electronic control unit 1B is constituted of aninput interface (input I/F) 11, the arithmetic processing section 10, aradio communication control section 12, and an antenna 13. Thearithmetic processing section 10 captures signals obtained by processingsignals sent from the sensors 2 from the input I/F 11, performspredetermined operations, and outputs an optimum control signal to theactuator drivers 4 through the radio communication control section 12and antenna 13. The actuator drivers 4B receive the signals through anantenna 8 to drive the actuators 3 a.

Furthermore, as shown in FIG. 7, the actuator drivers 4B respectivelyinclude an N-type power MOS transistor 20, a Zener diode 21, a groundshort-circuit diagnosis circuit 23 for load disconnection or a drain D,a power-supply short-circuit diagnosis circuit 24 for overcurrent or thedrain D, and overheat diagnosis circuit 25 and a diagnosis outputcontrol circuit 26 respectively serving as a self-diagnosis section, agate protection circuit 22 serving as a self-protection section, a radiocommunication control section 29 serving as a communication controlsection, an antenna 8, and a timer circuit 28 serving as a timersection. Furthermore, when the ground short-circuit diagnosis circuitfor load disconnection or the drain D, the power-supply short-circuitdiagnosis circuit 24, or the self-diagnosis circuit of the overheatdiagnosis circuit 25 serving as the self-diagnosis section detects anabnormal state corresponding to each circuit, it outputs a signalshowing the abnormal state to the diagnosis output control circuit 26and the diagnosis output control circuit 26 outputs a signalcorresponding to each abnormal state to the electronic control unit 1through the radio communication control section 29.

As described above, the timer circuit 28 is indispensable to performmultiplex communication through time-sharing. However, the circuit 28 isnot always necessary when individually communicating between theelectronic control unit 1B and the actuator drivers 4B by using radiocommunication lines having frequencies different from each other.

FIG. 8 shows a car 50 using the vehicle control system 60 of the firstembodiment in which the independent actuator drivers 4 are dispersedcorrespondingly to the actuators 3 a to be driven.

In the case of the car 50, an engine control unit serving as anelectronic control unit 1 is set not in a cabin 52 but in an engine room51 having a severer temperature environment in order to reduce theharness cost and man-hours for assembling the car, in which thearithmetic processing section 10 of an electronic control unit 1performs various operations in accordance with output signals of varioussensors 2 such as an engine-speed sensor, water-temperature sensor, andintake-air-flow sensor, outputs a driving signal to actuator drivers 4for driving an ignition coil, an injector, and various valves through aserial communication line 5 to perform optimum control of an engine.Also in the case of a car using the vehicle control system 60A of thesecond embodiment or the vehicle control system 60B of the thirdembodiment, it is also possible to perform optimum control an enginesimilarly to the case of the above described.

As described above, the embodiments of the present invention have thefollowing functions in accordance with the above configurations.

That is, the vehicle control systems 60, 60A, and 60B of the first tothird embodiments make it possible to control the heat produced in theelectronic control units 1, 1A, and 1B because the actuator drivers 4,4A, and 4B are arranged separately from the electronic control units 1,1A, and 1B. Therefore, radiation components such as a heat sink and aradiation fin are unnecessary for the electronic control units 1, 1A,and 1B and thus, it is possible to reduce the cost of an electroniccontrol unit.

The above mentioned is more effective for a car in which thespecification of a temperature environment is particularly severe for anelectronic control unit.

Moreover, because the actuator drivers 4, 4A, and 4B producing much heatare dispersed correspondingly to the actuators 3 a to be driven by thedrivers 4, 4A, and 4B, the heat to be produced by each of the actuatordrivers 4, 4A, and 4B becomes comparatively less. Therefore, it ispossible to easily take actions for radiation of an actuator driver atthe actuator-3 a side and downsize the electronic control units 1, 1A,and 1B, and moreover improve the versatility of the electronic controlunits 1, 1A, and 1B because the same electronic control unit can be usedfor actuators different in systems.

Furthermore, because of setting the actuator drivers 4, 4A, and 4B tothe actuator-3 a side, no large current flows through signal linesbetween the electronic control units 1, 1A, and 1B on one hand and theactuators 3 a on the other. Therefore, it is possible to reduceradiation noises from the vehicle control systems 60, 60A, and 60B.

Furthermore, by using the independent actuator drivers 4, 4A, and 4B bywhich an actual system can be constructed even if the drivers are set tothe outside of an electronic control unit, it is possible to securelyconstruct an actuator-driver-dispersed-type system and keep thereliability and functionality of the vehicle control systems 60, 60A,and 60B even if actuator drivers are dispersed.

Furthermore, because each of the actuator drivers 4, 4A, and 4B occupiesonly a comparatively small area even if including self-diagnosis andself-protection functions, a timer circuit, and a communication controlsection, it is possible to reduce the cost and size of the whole vehiclecontrol system by a value equivalent to downsizing of an electroniccontrol unit without changing sizes of the dispersed actuator drivers 4,4A, and 4B.

Furthermore, because the actuator drivers 4, 4A, and 4B are built inconnectors 3 b, it is possible to share actuators 3 a by differentsystems by constituting the actuator drivers 4, 4A, and 4B separatelyfrom the actuators 3 a and thereby, improve the versatility of actuators3 a.

Furthermore, when considering that the actuators 3 a include variousshapes, it can be said that it is superior in productivity to set thedriver 4 in the connector 3 a whose structure is comparatively simpleand which has less variation compare to the case of setting the driver 4by changing the housing structure every type. Furthermore, it isconsidered that the temperature around the actuator driver 4 is loweredand it is possible to more easily take actions for radiation by settingthe driver 4 in the connector 3 b compared to the case of setting it inthe actuator 3 a.

Furthermore, because the vehicle control system 60 of the firstembodiment is an actuator-driver-dispersed-type system using serialcommunication and is decreased in the number of wirings, it is possibleto reduce the wiring cost, wiring weight, and vehicle-assemblingman-hours. Furthermore, because the vehicle control system 60A of thesecond embodiment an actuator-driver-dispersed-type system using theserial communication line 5 and parallel communication line 6, it ispossible to completely correspond to the case in which real-timeprocessing is requested. Furthermore, because the vehicle control system60B of the third embodiment is an actuator-driver-dispersed-type systemusing radio communication, it is possible to reduce the number of signallines and further reduce the cost of the vehicle control system.

Furthermore, the car 50 using the vehicle control systems 60, 60A, and60B can be produced at a low cost because actions for radiation can beeasily taken and the versatility of the electronic control units 1, 1A,and 1B is increased by dispersing the actuator drivers 4, 4A, and 4Bthough the temperature in the engine room 51 becomes higher than that inthe cabin 52.

Though three embodiments of the present invention are described above,the present invention is not restricted to the embodiments. Variousmodifications can be designed as long as they are not deviated from thegist of the present invention described in claims.

For example, in the case of each of the above embodiments, the actuatordrivers 4, 4A, and 4B are built in the connectors 3 b. However, it isalso permitted that the actuator drivers 4, 4A, and 4B are built inadapters connected to the actuators 3 a. In this case, it is possible toconstruct a control system only by connecting the adapters to theexisting actuators 3 a and improve the productivity of the system.Moreover, it is permitted that the actuator drivers 4, 4A, and 4B arebuilt in the actuators 3 a. Also in this case, the same advantage can beobtained.

Furthermore, the actuator drivers 4, 4A, and 4B are not restricted tothe case of being built in the connectors 3 b. It is also permitted thatthe drivers 4, 4A, and 4B are removably mounted on outsides of theconnectors 3 b connected to the actuators 3 a or outsides of theadapters and electrically connected with the connectors 3 b or terminalsof the adapters.

FIG. 9 is a sectional view showing a state in which a dispersed actuatordriver 4 is removably mounted on the outside of a connector 3 b, inwhich a signal line 5 or 6 extended from an electronic control unit 1 isconnected to a connector terminal 42 and a connector at the actuator-3 aside is connected to a connector terminal 43.

Moreover, the connector terminals 42 and 43 are protruded beyond theconnector 3 b. By fitting an actuator driver 4 provided with aself-diagnosis section to the connector terminals 42 and 43, theactuator driver 4 is electrically and mechanically connected with theconnector terminals 42 and 43. Thus, by removably mounting the actuatordriver 4 on the outside of the connector 3 b, it is possible to changeonly the actuator driver 4 without changing the connector 3 b.Therefore, an advantage is obtained that the above case is superior inproductivity and maintainability.

FIG. 10 shows a mounting mode when an actuator driver 4 is built in aconnector 3 b, which is a sectional view of a driver-included connectorusing a lead frame.

A signal line 5 or 6 extended from an electronic control unit 1 isconnected to a connector terminal 42 and a connector at the actuator-3 aside is connected to a connector terminal 43.

Then, the actuator driver 4 provided with a self-diagnosis sectionserves as a one-chip IC or a multi-chip IC constituted of a plurality ofICs fabricated on a silicon wafer serving as a semiconductor substrateby using a BCD process in which a bipolar process, a power semiconductorprocess (DMOS process), and a CMOS process are united.

This IC is bonded onto a metallic member (metallic base) 40 of a leadframe by a conductive adhesive not through a substrate. The IC servingas the driver 4 is wire-bonded with the connector terminals 42 and 43 byan aluminum wire or gold wire 41 and then, the driver-included connector3 b is integrally formed by using a resin 44 and therebytransfer-molding the whole.

The metallic base 40 is exposed toward the outside of the connector 3 b,which also functions as a radiation plate of the IC serving as thedriver 4 but the radiation performance of the base 40 is notdeteriorated by mold-mounting it. Moreover, by integrally forming theactuator driver 4 and the connector 3 b through transfer-mold mounting,it is possible to realize the driver-included connector 3 b at a lowcost by decreasing the number of fabrication steps. It is also permittedto form the actuator driver 4 integrally with the adapter or actuator.

As understood from the above description, in the case of a vehiclecontrol system of the present invention, actuator drivers are dispersedto the actuator side and made independent. Therefore, it is possible toreduce the cost of the control system by controlling the heat producedin an electronic control unit and keep the reliability and functionalityof the control system after the actuator drivers are dispersed.

Moreover, by using the above-described vehicle control system, it ispossible to produce a low-cost car.

Although the present invention has been illustrated and described withrespect to exemplary embodiment thereof, it should be understood bythose skilled in the art that the foregoing and various other changes,omission and additions may be made therein and thereto, withoutdeparting from the spirit and scope of the present invention. Therefore,the present invention should not be understood as limited to thespecific embodiment set out above but to include all possibleembodiments which can be embodied within a scope encompassed andequivalent thereof with respect to the feature set out in the appendedclaims.

1. A vehicle control system comprising: plural actuators; an central control unit for outputting a control signal to said actuators; actuator drivers provided on each of said actuators, said actuator driver having a self-diagnosis section for diagnosing an abnormality of said actuator, a self-protection section for preventing said actuator driver itself from destruction caused by an abnormality of said actuators, and a communication control section for controlling a communication to said central control unit, and said actuator drivers for driving said actuators in accordance with said control signal from said central control unit; wherein said self-diagnosis section comprises a diagnosis output control section for outputting an abnormal signal in response to a diagnosed abnormal state, and said diagnosis output control section output said abnormal signal to said central control unit via said communication control section.
 2. A vehicle control system according to claim 1, wherein at least one of said actuator drivers has a timer section; and said timer section carries out a PWM driving or a pulse driving to said actuators in accordance with said control signal from said central control unit.
 3. A vehicle control system comprising: at least two actuators selected from an ignition coil for controlling an ignition of an internal combustion engine, an injector for controlling a fuel injection amount, and an actuator for controlling an opening and a closing of a valve of said internal combustion engine; an engine control unit for outputting a control signal to said actuators, actuator drivers provided on each of said actuator, said actuator driver having a self-diagnosis section for diagnosing an abnormality of said actuator, a self-protection section for preventing said actuator driver itself from destruction caused by an abnormality of said actuators, and a communication control section for controlling a communication to said engine control unit, and said actuator drivers for driving said actuators in accordance with said control signal from said engine control unit; wherein said self-diagnosis section comprises a diagnosis output control section for outputting an abnormal signal in response to a diagnosed abnormal state, and said diagnosis output control section output said abnormal signal to said engine control unit via said communication control section.
 4. A vehicle control system according to claim 3, wherein said actuator driver for driving said injector has a timer section; and said timer section carries out a pulse driving to said actuators in accordance with said control signal from said engine control unit.
 5. A vehicle control system according to claim 3, wherein said actuator driver for driving said valve has a timer section; and said timer section carries out a PWM driving to said actuators in accordance with said control signal from said engine control unit.
 6. A vehicle control system according to claim 1, wherein said actuator drivers are built in connectors and adaptors connected to said actuators.
 7. A vehicle control system according to claim 1, wherein said actuator drivers are mounted removably on outsides of connectors and adaptors connected to said actuators and connected electrically with terminals of said connectors and said adaptors.
 8. A vehicle control system according to claim 1, wherein said actuator drivers are built in said actuators.
 9. A vehicle control system according to claim 1, wherein said communication control section of said actuator driver has a serial communication control section.
 10. A vehicle control system according to claim 1, wherein said communication control section of said actuator driver has a radio communication control section.
 11. A vehicle control system according to claim 1, wherein said actuator drivers being fabricated on a semiconductor substrate as an IC.
 12. A vehicle control system according to claim 6, wherein said actuator drivers being mounted directly on a metallic member not through a substrate and formed integrally with said connectors or said adaptors connected to said actuators or formed integrally with said actuators.
 13. A vehicle control system according to claim 1, wherein said self-diagnosis section comprises a grand short-circuit diagnosis for diagnosing a load disconnection of said actuators, an over current diagnosis section for diagnosing an over current, and an overheat diagnosis section for diagnosing an overheat of said actuator driver.
 14. A vehicle control system comprising: plural actuators; an central control unit for outputting a control signal to said actuators; actuator drivers constituted as an IC built in each of said actuator, said actuator driver having a self-diagnosis section for diagnosing an abnormality of said actuator, a self-protection section for preventing said actuator driver itself from destruction caused by an abnormality of said actuators, and a communication control section for controlling a communication to said central control unit, and said actuator drivers for driving said actuators in accordance with said control signal from said central control unit; wherein said self-diagnosis section comprises a diagnosis output control section for outputting an abnormal signal in response to a diagnosed abnormal state, and said diagnosis output control section output said abnormal signal to said central control unit via said communication control system. 